Field of the Invention
The present invention relates to an illumination apparatus and a projection type display apparatus.
Description of the Related Art
A so-called solid-state light source projector, which has recently been developed, irradiates as excitation light a beam emitted from a laser diode (referred to as a “LD” hereinafter) onto a fluorescent substance (phosphor), and uses wavelength-converted fluorescent light for light source light. Japanese Patent Laid-Open No. (“JP”) 2012-137608 discloses this type of projector.
The projector disclosed in JP 2012-137608 includes a blue LD as an excitation light source, a light emitting element provided on a blue diffusion layer, a green fluorescent substance (phosphor) layer, and a red fluorescent substance layer on three circumferences having different diameters, and a dichroic mirror configured to combine light fluxes from the light emitting element with one another. This configuration can guide the red, green, and blue light fluxes to the illumination optical system.
In general, the fluorescent light emitted from the fluorescent substance has a broadband spectral distribution, and thus the spectral distributions from the red and green fluorescent substances have an overlapping wavelength band. Thus, the configuration disclosed in JP 2012-137608 that combines the light fluxes from two different fluorescent substances through the dichroic mirror causes a loss in the overlapping wavelength band in the spectral distribution between these two different fluorescent substances.